There are known conventional information display apparatuses that display in an optical path of a viewing optical system information on the viewing optical system etc. so that the information can be observed together with an optical image formed by the viewing optical system. In particular, a scanning display apparatus that forms an electronic image on the retina of a viewer's eye using a scanning optical system to make it possible to view an electronic image together with an optical image has been proposed. (See for example, United States Patent Application No. 20010034077.)
However, the above-mentioned example of the scanning display apparatus suffers from a first problem that it is so large in size that it is difficult to build it in an small-size viewing optical system (such as a viewfinder) of a camera or a telescope or the like, since the scanning display apparatus is composed of optical components including a plurality of reflecting mirrors.
Furthermore, in conventional digital single lens reflex cameras, users take a photograph while viewing an image of the subject through a viewfinder, and have an image picked up by an image pickup element displayed in the viewfinder by means of a display device such as a liquid crystal display to check it (see for example, Japanese Patent Application Laid-open No. 6-245114). In this display method, since what is used for displaying photographed images is a liquid crystal display device, there is a second problem that resolution and saturation reproducibility are not good, and it is difficult for the user to examine whether or not a picked up image has desired image quality.
Still further, a conventional apparatus that displays an electronic image in an optical path of a viewing optical system to make it possible to view the electronic image together with an optical image formed by the viewing optical system is known from Japanese Patent Application Laid-Open No. 11-174367. However, since the display apparatus disclosed in Japanese Patent Application Laid-Open No. 11-174367 utilizes internal reflection of a prism member, it suffers from a third problem that light such as undesired reflected light from a reflection surface of the prism member that is not intended is incident on a view's eye and seen as a ghost.
In view of the above-mentioned first problem, a first object of the present invention is to provide a compact scanning display apparatus that can be built in an optical path of a viewing optical system and a camera equipped with such a scanning display apparatus.
In view of the above-mentioned second problem, a second object of the present invention is to provide a camera equipped with a display apparatus having high image quality.
In view of the above-described third problem, a third object of the present invention is to provide a compact display apparatus in which ghost is not formed.
To achieve the first object, according to the first aspect of the present invention there is provided a scanning display apparatus comprising superimposition means disposed in an optical path of a viewing optical system through which an image of an object is viewed, the superimposition means making an electronic image viewable in such a way as to be superimposed on said image of the object, a micro lens array disposed on an incidence end surface of said superimposition means on which said electronic image is incident, a light source for said electronic image, light condensing means for condensing light from said light source onto said micro lens array, and scanning means for scanning said micro lens array with said light, wherein an image formed on said micro lens array is made viewable.
To achieve the above-mentioned first object, according to a second aspect of the present invention, there is provided a scanning display apparatus comprising, superimposition means disposed in an optical path of a viewing optical system through which an image of an object is viewed, the superimposition means making an electronic image viewable in such a way as to be superimposed on said image of the subject, a light source for said electronic image, light condensing means for condensing light from said light source onto an incidence end surface of said superimposition means, and scanning means for scanning said incidence end surface with said light, wherein said superimposition means includes a polarizing beam splitter disposed in the optical path of said viewing optical system that reflects light from said incidence end surface, a reflecting condenser member disposed in the optical path of said viewing optical system that transmits light of said viewing optical system and reflects light from said polarizing beam splitter., and a quarter-wave plate disposed between said polarizing beam splitter and said reflecting condenser member.
According to a third aspect of the present invention, in the scanning display apparatus according to the first aspect, it is preferred that said superimposition means includes a polarizing beam splitter disposed in the optical path of said viewing optical system that reflects light from said incidence end surface, a reflecting condenser member disposed in the optical path of said viewing optical system that transmits light of said viewing optical system and reflects light from said polarizing beam splitter, and a quarter-wave plate disposed between said polarizing beam splitter and said reflecting condenser member.
According to a fourth aspect of the present invention, in the scanning display apparatus according to the first or third aspect, it is preferred that said superimposition means includes a reflection type hologram disposed in the optical path of said viewing optical system, said reflection type hologram reflecting light from said micro lens array.
In the scanning display apparatus according to the first, third or fourth aspect of the present invention, it is preferred that said micro lens array be carved on said incidence end surface of a plane parallel optical member, or said micro lens array be molded and attached on said incidence end surface.
In the scanning display apparatus according to the first, third or fourth aspect of the present invention, it is preferred that said micro lens array be composed of a hologram device.
In the scanning display apparatus according to the second or third aspect of the present invention, it is preferred that said reflecting condenser member be composed of a hologram device.
In the scanning display apparatus according to the first or second aspect of the present invention, it is preferred that said scanning means be composed of a movable mirror or an acoustooptic device.
In the scanning display apparatus according to the first or second aspect of the present invention, it is preferred that the axis of incidence of light from said light source to said scanning means and the optical axis of said viewing optical system be oriented in substantially the same direction.
In the scanning display apparatus according to the first or second aspect of present invention, it is preferred that the axis of incidence of light from said light source to said scanning means and the optical axis of said viewing optical system be substantially perpendicular, and a half-wave plate be provided between said scanning means and said polarizing beam splitter.
According to a fifth aspect of the present invention, there is provided a camera equipped with said scanning display apparatus.
To achieve the above-mentioned second object, according to a sixth aspect of the present invention, there is provided a camera comprising a viewing optical system that makes an image of a subject formed through a taking optical system viewable, an image pickup means for picking up said image of the subject, reproduction means for reproducing an image of the subject picked up by said image pickup means, introduction means disposed on the optical axis of said viewing optical system for introducing an image reproduced by said reproduction means onto the optical axis of said viewing optical system to make it viewable, and limiting means for limiting a light flux entering said viewing optical system from said taking optical system.
In the camera according to the sixth aspect of the present invention, it is preferred that said image of the subject and said reproduced image be viewable in a superimposed manner.
In the camera according to the sixth aspect of the present invention, it is preferred that said limiting means be composed of a quick return mirror that selectively guides a light flux from said taking optical system to said viewing optical system, and that when an image is introduced into said viewing optical system by said introduction means, said limiting means blocks a light flux traveling from said taking optical system to said viewing optical system.
In the camera according to the sixth aspect of the present invention, it is preferred that said limiting means be light quantity limiting means for limiting the quantity of a light flux that forms said image of the subject, and that when an image is projected in said viewing optical system by said introduction means, said limiting means limits a light flux traveling from said taking optical system to said viewing optical system.
In the camera according to the sixth aspect of the present invention, it is preferred that the camera further comprise image processing means for applying characterization on at least a part of said reproduced image.
In the camera according to the sixth aspect of the present invention, it is preferred that said display member can display an image representing control information of said camera.
To achieve the above-mentioned third object, according to a seventh aspect of the present invention, there is provided a display apparatus comprising, an optical member having a flat-plate shape disposed in an optical path of a viewing optical system in such a way that its flat surface is substantially perpendicular to the optical axis of said optical path, said flat surface constituting an optical waveguide, image forming means disposed in the vicinity of an end surface of said optical member, a polarizing plate disposed between said image forming means and the end surface of said optical member, a polarizing beam splitter for separating, among image light fluxes entering into said optical member from said image forming means, a light flux that is polarized in a predetermined direction by said polarizing plate, and a quarter-wave plate disposed on said flat surface, wherein among light fluxes propagating in said optical member, a reflected light flux that has passed through said quarter-wave plate is separated by said polarizing beam splitter toward a direction that is different from the direction of said separation.
To achieve the above-mentioned third object, according to an eighth aspect of the present invention, there is provided a display apparatus comprising an optical member having a flat-plate shape disposed in an optical path of a viewing optical system in such a way that its flat surface is substantially perpendicular to the optical axis of said optical path, said flat surface constituting an optical waveguide, image forming means disposed in the vicinity of an end surface of said optical member, a reflection member that reflects an image light flux entering into said optical member from said image forming means toward said viewing optical system, and a light regulating member disposed on said flat surface that transmits a light flux incident on said flat surface substantially perpendicularly and reflects a light flux incident on said flat surface at a predetermined angle to a direction different from the direction of incidence, wherein among light fluxes propagating in said optical member, a light flux traveling toward said flat surface is separated by said light regulating member toward a direction different from said reflection member.
To achieve the above-mentioned third object, according to a ninth aspect of the present invention, there is provided a display apparatus comprising an optical member having a flat-plate shape that constitutes an optical waveguide, a polarizing beam splitter formed inside said optical member that reflects, among light fluxes propagating in said optical member, a light flux that is polarized in a specific direction, and a quarter-wave plate disposed on a surface of said optical member, wherein among light fluxes propagating in said optical member, a reflected light flux that has passed through said quarter-wave plate is transmitted through the polarizing beam splitter.
To achieve the above-mentioned third object, according to a tenth aspect of the present invention, there is provided a display apparatus comprising an optical member having a flat-plate shape that constitutes an optical waveguide, a polarizing beam splitter formed inside said optical member that transmits, among light fluxes propagating in said optical member, a light flux that is polarized in a specific direction, and a quarter-wave plate disposed on a surface of said optical member, wherein among light fluxes propagating in said optical member, a reflected light flux that has passed through said quarter-wave plate is reflected by the polarizing beam splitter.
To achieve the above-mentioned third object, according to a eleventh aspect of the present invention, there is provided a display apparatus comprising an optical member having a flat-plate shape that constitutes an optical waveguide, a polarizing beam splitter formed inside said optical member that separates, among light fluxes propagating in said optical member, a light flux that is polarized in a specific direction, and a quarter-wave plate disposed on a surface of said optical member, wherein among light fluxes propagating in said optical member, a reflected light flux that has passed through said quarter-wave plate is separated by said polarizing beam splitter toward a direction that is different from the direction of said separation.